Many efforts and a great deal of work have been made and done to reduce the contaminants emitted by the Otto and Diesel internal combustion engines in current use, such as carbon monoxide, unburned fuel, nitrogen oxides, lead compounds and solid particles; and some improvements have been obtained, but those engines continue to emit contaminants in intolerable quantities. The only practical solution achieved so far is to eliminate the contaminants by means of catalytic converters after they have already been formed, with the inconveniences of efficiency loss, generation of unusable heat and additional cost. Besides, the Diesel engines emit health harming solid particles that the converters cannot eliminate.
The main, problem of the current internal combustion engines is precisely that the combustion occurs in the cylinder "dead space"; this is the volume of the cylinder not swept by the piston. This space is a wafer, a cylinder of a very, small height and required to achieve the necessary compression. Its geometry is totally inadequate as a combustion chamber; within the volume of the dead space, the combustion gases encounter very hot zones where nitrogen oxides are formed and cold zones where the combustion is chilled. In spite of the improvements achieved, its inherent geometry makes it impossible to obtain a complete solution.
In the engine described in this invention, a complete combustion is accomplished with reduced production of contaminants, and with increased efficiency.
Several engines with combustion chambers or combustors external to the cylinders have been proposed. A well designed external combustor by itself can improve the combustion, but it can not reduce sufficiently the formation of nitrogen oxides. The applicant filed an application before the U.S. Patent Office about this principle on Mar. 2, 1971, Ser. No. 05/120,166, same that was not pursued because it was realized that it would not solve some of the major problems.
Other prior art documents related with the field of the invention are as follows:
U.S. Pat. No. 2,140,085 to Maina, dated Dec. 13, 1938 discloses an engine in which the water is forced through a coiled thread in order to heat and vaporize the water, inject it into the combustor or pressure generator, mix it with the combustion gases and expand the mixture in the power cylinder. Here, the heat transmitted to the water is taken from the energy of the combustion gases reducing their capacity to generate mechanical energy. As only a fraction of the heat transmitted can be recuperated as mechanical energy when the additional steam produced by the injected water is expanded in the power cylinder, the efficiency of the cycle is reduced which is the opposite to the intention of the applicant invention.
In the applicant's invention the purpose of the combustor jacket is not to absorb heat because this would reduce the efficiency of the cycle even if the steam generated is injected in the combustor. The purpose is to maintain the inner wall of the combustor within a metal tolerable temperature range. The efficiency of the cycle is increased not because the heat transmitted to the jacket of the combustor is recuperated, but because the heat transmitted to the jackets of the power mechanism and the compressor is recuperated and a fraction of that heat is converted into mechanical energy in the power mechanism instead of being dissipated in a radiator.
Moreover, in the applicant's invention, an important feature is that the water injected is the same that cools all the jackets of the engine, and that by doing so the emission of contaminants is reduced and the efficiency of the cycle is increased. The invention of Maina includes besides the thread in the pressure generator, cooling jackets in the power cylinder, in the compressor and even around the thread in the pressure generator, but there is not any mention that could suggest that the water injected is the same that cools the jackets.
The invention of Maina does not include any means in the combustor to improve the combustion; and the disclosure does not make any mention of having the intention to reduce the formation of contaminants.
U.S. Pat. No. 2,404,395 to Milliken dated Jul. 23, 1946, discloses a low pressure compressor, a high pressure compressor, an external combustor, a high pressure engine, a low pressure engine, and a primary and a secondary heat exchanger. The air compressed by the low pressure compressor is the fluid that cools the jackets of the high pressure compressor and the high pressure engine. There is no water cooling, there is no water injection and there is no intention of reducing the formation of contaminants.
In the present invention the cooling medium is water and the cooling water is injected into the combustion gas stream to reduce the formation of contaminants and to increase the efficiency.
The invention of Milliken does not include any means in the combustor to improve the combustion.
Japanese Patent No. 52-3906 to Tanegashima, discloses an engine, which includes a compressor, an output generator, and a combustor external to the engine cylinder with several air inlets. It does not include any means to inject the water that cools the jackets of the engine into the combustor. The figures do not even show water jackets.
U.S. Pat. No. 4,255,927 to Johnson, dated Mar. 17, 1981, refers to a combustion system for gas turbines that includes a combustor with several excess air entrances in the reaction zone to produce fuel lean or fuel rich mixtures as required to lower the combustion temperature and reduce the formation of nitrogen oxides. Besides, it maintains an efficient combustion across a wide range of turbine loads by means of a mechanism that shifts the air flow as required between the reaction zone and the dilution zone. Intended as it is for turbine applications it does not include water cooled jackets, nor water injection.
U.S. Pat. No. 3,927,520 to Arvin, dated Dec. 23, 1975 refers to a turbine combustion apparatus adapted to reduce emissions for automotive applications. It includes a combustor with several air control entrances in a prechamber and in the reaction zone. Intended as it is for turbine application it does not include water cooled jackets, and no water injection.
U.S. Pat. No. 1,013,907 to Taylor, dated Jan. 9, 1912 discloses an engine which includes several power cylinders, an air pump and a combustor with water cooled jacket. The water that cools the jacket is injected in the combustor to turn it into steam so as to cool the products of combustion and thereby lower the temperature of the fluid supplied to the engine. The intention is that the temperature of the mix of the combustion products and steam have a temperature tolerable to the metal parts of the engine. The power cylinders have no water cooled jackets; neither does the air pump.
This invention does not include any means in the combustor to improve the combustion, and the intention of the inventor never was to reduce the formation of contaminants.
U.S. Pat. No. 1,302,582 to C. A. Norman, dated May 6, 1919 discloses one compressor cylinder, one combustion chamber and three expansion cylinders. The interior of the combustion chamber is lined with a refractory material. The cylinders of the compressor and the expansion cylinders have jackets. There is nothing that could suggest that the water injected is the same that cools the jackets.
The invention of Norman does not include any means in the combustor to improve the combustion, nor suggest the intention of reducing the formation of contaminants.
U.S Pat. No. 1,510,688 of A. La Fon, dated Oct. 7, 1924 discloses an engine which includes a compressor, an external combustor with a venturi exit and a work cylinder. The water that cools the jackets of the compressor and the combustor is injected in the venturi throat. In this invention the combustion products, will have their temperature reduced by the heat taken by the water which is converted into steam, and hence the engine, and its lubricants, will not be burned by excessively hot gases.
As the intention of La Fon is to reduce the temperature of the mix of the combustion gases and the steam produced by the water injected to a temperature tolerable by the metal parts of the engine, the work cylinder has no water cooled jackets. Moreover, the invention of La Fon does not include any means in the combustor to improve the combustion; and there is nothing in the disclosure that could suggest the intention to reduce the formation of contaminants.
U.S. Pat. No. 3,708,976 to Martin John Berlyn dated Jan. 9, 1973, refers to a vapor generator. It is an apparatus analogous to a boiler. It does not refer to an engine. It includes a compressor, an external combustor and an auxiliary expansion motor that drives the compressor.
Since the intention is to produce a fluid of temperature similar to that of a boiler, neither the compressor, the combustor nor the motor have jackets. Moreover, the invention of Berlyn does not include any means in the combustor to improve the combustion; and it is not intended to reduce the formation of contaminants.
U.S. Pat. No. 3,839,858 to VAN AVERMAETE dated Oct. 9, 1973, refers to a combustion reciprocating machine that provides an efficient and fast operating starting device and a reasonable output, no matter what the working conditions may be. It includes a two stage compressor with jackets, an external combustion chamber with jackets and a power cylinder with jackets. It does not make any mention to the water cooling of the jackets, nor to water being injected in the combustor, nor to an intention of reducing the formation of contaminants, or increasing the efficiency. The invention of Van Avermaete does not include any means in the combustor to improve the combustion; his description does not make any mention of having the intention to reduce the formation of contaminants.